β and A from fitting i0 to Epeak using the expression , activation energy (Ea) measured using the RDE method in 0.1 M KOH from this work and an H2-pump configuration from the study of Durst et al. (24), difference in Hupd desorption peak potentials (ΔEpeak) in 0.1 M KOH and acid with pH 0, and βEa calculated as [Ea (0.1 M KOH) − Ea (H2 pump)]/FΔEpeak.